...spring into existence without even the namespacing protection of different prefixes?

The extremely miniscule benefit of having same-named variables of different types
is one I would gladly trade for the reduction in typing and visual clutter.
Some people code according to style guidelines which explicitly discourage
the use of this feature — and for good reason, imho.

Note that in a name like $x, the keystrokes involved are three times
that necessary to type x. That really belies the alleged priority given to Huffman coding in the design of Perl.

Of course one will argue that good Perl coders don't use names that short;
but a keystroke penalty against them is not a good way to encourage better
behavior. The two keystoke penalty is incurred on every variable name
occurrence.

I think it also worth mentioning that the elimination of sigils would have
major PR benefit as well.

As for springing into existence — this (undeclared variables)
is the sort of behavior that the interpreter should be in the business
of discouraging. The penalty of having to declare a variable is incurred
only once per variable.

A word spoken in Mind will reach its own level, in the objective world, by its own weight

The extremely miniscule benefit of having same-named variables of different types is one I would gladly trade for the reduction in typing and visual clutter.

How much is the benefit of being able to look at a piece of code and identify which elements are variables and, of those, which are aggregates and which are scalars and which support which types of indexing operations? People will invent their own Hungarian notations without scalars, I promise you.

(undeclared variables) is the sort of behavior that the interpreter should be in the business of discouraging.

Somehow Ruby and Python don't manage that feature. It's awfully difficult if you allow lvalue functions and features such as method_missing.